Could ODM do the same thing with an additional parameter ?
So that is disregard the gps altitude and replace it by the NASA SRTM elevation data of the starting point + the above ground level (AGL) barometric altitude ?
That way you would get the GPS position but the better altitude.
I suppose ODM could do something like this, but the same can be other ways by offsetting the gps altitude and absolute altitude values of the DJI metadata using exiftool.
Using a centrally located image from your dataset, take the gsp location from the image determine the elevation on the usgs website to determine ASL elevation. By adding the DJI relative altitude to the DJI GPS altitude and Absolute Altitude metadata, you should get relatively close. ODM will subtract the relative altitude from the gps altitude to determine ASL elevation in regards to elevation.
But nothing works quite as good as using surveyed GCP’s if you have that capability.